bjoernager/rust
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Add add/sub methods that only panic with debug assertions to rustc

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This mitigates the perf impact of enabling overflow checks on rustc.
The change to use overflow checks will be done in a later PR.
This commit is contained in:
Nilstrieb 2024-03-28 20:27:12 +01:00
parent c3b05c6e5b
commit 5039160c5b
6 changed files with 109 additions and 27 deletions
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8
compiler/rustc_span/src/span_encoding.rs
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@ -5,6 +5,10 @@ use crate::{BytePos, SpanData};
use rustc_data_structures::fx::FxIndexSet;
// This code is very hot and uses lots of arithmetic, avoid overflow checks for performance.
// See https://github.com/rust-lang/rust/pull/119440#issuecomment-1874255727
use rustc_serialize::int_overflow::DebugStrictAdd;
/// A compressed span.
///
/// [`SpanData`] is 16 bytes, which is too big to stick everywhere. `Span` only
@ -166,7 +170,7 @@ impl Span {
debug_assert!(len <= MAX_LEN);
SpanData {
lo: BytePos(self.lo_or_index),
hi: BytePos(self.lo_or_index + len),
hi: BytePos(self.lo_or_index.debug_strict_add(len)),
ctxt: SyntaxContext::from_u32(self.ctxt_or_parent_or_marker as u32),
parent: None,
}
@ -179,7 +183,7 @@ impl Span {
};
SpanData {
lo: BytePos(self.lo_or_index),
hi: BytePos(self.lo_or_index + len),
hi: BytePos(self.lo_or_index.debug_strict_add(len)),
ctxt: SyntaxContext::root(),
parent: Some(parent),
}